I'm not going to buy this one because it is too far from home, but would I have trouble loading a 977 track loader with big grousers on this trailer? Not sure if I'm more worried about going over the tires or the metal on metal.
Should be fine, sometimes you gotta weld some rebar or something on for the track shoes to catch. The tires won't care.
I second what lantraxco said
The beavertail looks to have been added on. It would probably be fine but some support (blocks) under the end of the beavertail may be beneficial.